我们收到了一个非常礼貌的回复。

We received a very ___courteous reply.

图书馆员工值得祝贺：他们都非常礼貌且乐于助人。

The library staff deserve congratulations: they are all very ___courteous and helpful.

他对同事总是很礼貌。

He is always ___courteous to his colleagues.